"I don't think this is a big issue. We have bigger fish to fry," he told Reuters, a day after euro zone lenders put a short-term debt relief deal for Greece on hold in response to Athens' proposal for the one-off payout.

Speaking in Berlin, Tsakalotos said Europe needed to show it could solve its own problems in order to restore confidence among working-class people after populist gains in a series of European elections, the Brexit vote and the Italian referendum.